Refuse collection vehicles generally have a body supported by wheels for containing compacted refuse within a chamber within the body. In rear-loading refuse vehicles, a tailgate assembly is mounted on the rearward portion of the refuse vehicle body. The tailgate assembly generally includes a hopper for receiving refuse and an opening at the forward portion of the hopper which communicates with the refuse-containing chamber. The tailgate assembly also generally includes a refuse compaction mechanism for sweeping refuse from within the hopper into the refuse vehicle body. In addition to sweeping the refuse from the hopper, the compaction mechanism urges the refuse forward into the chamber of the body, thereby compacting the refuse within the chamber.
The hopper of a tailgate assembly is adapted to receive refuse containers of various sizes which are either supported by an operator who dumps a container into the hopper or by a lifting mechanism which vertically hoists the container above the hopper and then inverts the container to dump the refuse into the hopper. Such lifting mechanisms, which are particularly popular in Europe, are usually mounted at the rearmost portion of the tailgate mechanism so that refuse containers can be readily attached and released at ground level.
Conventional tailgate assemblies, such as those described in U.S. Pat. Nos. 3,786,946, and 4,460,307, are generally unsuitable for use in combination with rear-mounted lifting mechanisms. In the tailgate assembly disclosed in U.S. Pat. No. 3,786,946, a transverse beam extends across the upper portion of the rearmost edge of tailgate. The transverse beam impedes refuse containers from being hoisted and inverted above the hopper by lifting mechanisms. Similarly, in the tailgate assembly disclosed in U.S. Pat. No. 4,460,307, a rigid cross member extends across the upper portion of the rearmost edge of the tailgate, impeding the hoisting and inverting of refuse containers above the hopper by lifting mechanisms.
In connection with the compaction mechanism of tailgate assemblies, it is generally necessary for the packer panel to have at least two travel paths: the first to accommodate the handling of bulky objects (such as appliances), and the second to limit the vertical rotation of the packer panel in order to clear containers and container covers in their dumped positions to make it possible to dump a container at any time during a packing cycle.
To provide the above two travel paths, the compaction mechanism is supported by a swing-link arrangement including a packer panel pivotally connected to an upper shield swing-link and to a lower link pivotally connected to the rear of the tailgate. For the bulky object mode, the packer panel pivots full up and in its rearmost pivoted position is well above the hopper loading lip in order to provide maximum clearance over an object in the hopper. For the container mode, the packer panel is restricted in its vertical rotation so as to swing to the rear, thereby remaining under and clear of containers and container covers.
The combination of programmable logic controllers with swing-link compaction mechanisms provides additional benefits in the collection and transportation of refuse materials. In this regard, programmable logic controllers can actuate certain extensible components of the compaction mechanism so as to induce the compaction mechanism to travel a first path as described above for the bulky object mode and, alternatively, to travel a second path as described above for the container mode.
Accordingly, it is an object of the present invention to provide a tailgate assembly for a refuse collection vehicle which includes a swing-link compaction mechanism and which accommodates rear-mounted lifting mechanisms for refuse containers.
It is also an object of the invention to provide a tailgate assembly for a refuse collection vehicle which includes a swing-link compaction mechanism and which includes a large, substantially unobstructed upper portion for accommodating refuse containers hoisted and inverted above the hopper by lifting mechanisms.
It is a further object of the invention to provide a tailgate assembly for a refuse collection vehicle which includes a swing-link compaction mechanism and programmable controls for actuating certain extensible components of the compaction mechanism to direct the compaction mechanism along a number of predetermined travel paths.